Today's trend is to configure separate networks for management, virtual machines (VMs) and migration of VMs in virtual datacenters. Typically, in such virtual datacenters a set of virtualization-based distributed infrastructure services provides virtual machine monitoring and management to automate and simplify provisioning, optimize resource allocation, and provide operating system and application-independent high availability to applications at lower cost and without the complexity of solutions used with static, physical infrastructure and other such environments. One of these distributed services is a failover service, which provides easy-to-manage, cost-effective (high availability) HA clusters for all applications running on VMs that are often used for critical databases, file sharing on a network, business applications, and customer services, such as electronic commerce websites. In the event of a server hardware failure, affected VMs are automatically restarted on other physical servers during a failover operation to reduce downtime and information technology (IT) service disruption and to further reduce any dedicated standby hardware and installation of additional software requirements.
However, if a host computing system is partially isolated (i.e., isolated from management and not the migration and virtual machine network) from the other host computing systems in a high availability (HA) cluster in the virtual datacenter, any VMs running on the partially isolated host computing system are disconnected from the virtual management system (SMS). In such a scenario, any VMs running on the partially isolated host are kept powered on may not have VM and host management functions, such as virtual machine monitoring and management to automate and simplify provisioning, optimize resource allocation, and provide operating system and application-independent high availability to applications as the management network is isolated from the failed host computing system.